X-Git-Url: https://git.cameronkatri.com/cgit.git/blobdiff_plain/6ceba453a27ead382d0116d95bdeb6b6be1149e2..c4fbb99cee30fa295e240b429b2dc7e8ad83d535:/cache.c

diff --git a/cache.c b/cache.c
index 801e63f..2c70be7 100644
--- a/cache.c
+++ b/cache.c
@@ -13,22 +13,23 @@
  *
  */
 
-#ifdef HAVE_LINUX_SENDFILE
-#include <sys/sendfile.h>
-#endif
 #include "cgit.h"
 #include "cache.h"
 #include "html.h"
+#ifdef HAVE_LINUX_SENDFILE
+#include <sys/sendfile.h>
+#endif
 
 #define CACHE_BUFSIZE (1024 * 4)
 
 struct cache_slot {
 	const char *key;
-	int keylen;
+	size_t keylen;
 	int ttl;
 	cache_fill_fn fn;
 	int cache_fd;
 	int lock_fd;
+	int stdout_fd;
 	const char *cache_name;
 	const char *lock_name;
 	int match;
@@ -44,7 +45,7 @@ struct cache_slot {
 static int open_slot(struct cache_slot *slot)
 {
 	char *bufz;
-	int bufkeylen = -1;
+	ssize_t bufkeylen = -1;
 
 	slot->cache_fd = open(slot->cache_name, O_RDONLY);
 	if (slot->cache_fd == -1)
@@ -61,8 +62,9 @@ static int open_slot(struct cache_slot *slot)
 	if (bufz)
 		bufkeylen = bufz - slot->buf;
 
-	slot->match = bufkeylen == slot->keylen &&
-	    !memcmp(slot->key, slot->buf, bufkeylen + 1);
+	if (slot->key)
+		slot->match = bufkeylen == slot->keylen &&
+		    !memcmp(slot->key, slot->buf, bufkeylen + 1);
 
 	return 0;
 }
@@ -161,10 +163,23 @@ static int close_lock(struct cache_slot *slot)
  */
 static int lock_slot(struct cache_slot *slot)
 {
-	slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT | O_EXCL,
+	struct flock lock = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_SET,
+		.l_start = 0,
+		.l_len = 0,
+	};
+
+	slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT,
 			     S_IRUSR | S_IWUSR);
 	if (slot->lock_fd == -1)
 		return errno;
+	if (fcntl(slot->lock_fd, F_SETLK, &lock) < 0) {
+		int saved_errno = errno;
+		close(slot->lock_fd);
+		slot->lock_fd = -1;
+		return saved_errno;
+	}
 	if (xwrite(slot->lock_fd, slot->key, slot->keylen + 1) < 0)
 		return errno;
 	return 0;
@@ -183,6 +198,13 @@ static int unlock_slot(struct cache_slot *slot, int replace_old_slot)
 	else
 		err = unlink(slot->lock_name);
 
+	/* Restore stdout and close the temporary FD. */
+	if (slot->stdout_fd >= 0) {
+		dup2(slot->stdout_fd, STDOUT_FILENO);
+		close(slot->stdout_fd);
+		slot->stdout_fd = -1;
+	}
+
 	if (err)
 		return errno;
 
@@ -194,11 +216,9 @@ static int unlock_slot(struct cache_slot *slot, int replace_old_slot)
  */
 static int fill_slot(struct cache_slot *slot)
 {
-	int tmp;
-
 	/* Preserve stdout */
-	tmp = dup(STDOUT_FILENO);
-	if (tmp == -1)
+	slot->stdout_fd = dup(STDOUT_FILENO);
+	if (slot->stdout_fd == -1)
 		return errno;
 
 	/* Redirect stdout to lockfile */
@@ -208,16 +228,12 @@ static int fill_slot(struct cache_slot *slot)
 	/* Generate cache content */
 	slot->fn();
 
-	/* update stat info */
-	if (fstat(slot->lock_fd, &slot->cache_st))
-		return errno;
-
-	/* Restore stdout */
-	if (dup2(tmp, STDOUT_FILENO) == -1)
+	/* Make sure any buffered data is flushed to the file */
+	if (fflush(stdout))
 		return errno;
 
-	/* Close the temporary filedescriptor */
-	if (close(tmp))
+	/* update stat info */
+	if (fstat(slot->lock_fd, &slot->cache_st))
 		return errno;
 
 	return 0;
@@ -292,7 +308,7 @@ static int process_slot(struct cache_slot *slot)
 	/* If the cache slot does not exist (or its key doesn't match the
 	 * current key), lets try to create a new cache slot for this
 	 * request. If this fails (for whatever reason), lets just generate
-	 * the content without caching it and fool the caller to belive
+	 * the content without caching it and fool the caller to believe
 	 * everything worked out (but print a warning on stdout).
 	 */
 
@@ -367,6 +383,7 @@ int cache_process(int size, const char *path, const char *key, int ttl,
 	strbuf_addstr(&lockname, ".lock");
 	slot.fn = fn;
 	slot.ttl = ttl;
+	slot.stdout_fd = -1;
 	slot.cache_name = filename.buf;
 	slot.lock_name = lockname.buf;
 	slot.key = key;
@@ -398,7 +415,7 @@ int cache_ls(const char *path)
 	DIR *dir;
 	struct dirent *ent;
 	int err = 0;
-	struct cache_slot slot = { 0 };
+	struct cache_slot slot = { NULL };
 	struct strbuf fullname = STRBUF_INIT;
 	size_t prefixlen;